A pale blue
"This may be the first Iroshizuku that I don't really care for. The performance and characteristics are stellar, of course. It's the color: This is a rather weak, unsaturated blue.
My advice: For a beautiful, professional blue ink from Pilot, look for the Iroshizuku Asa Gao (""Morning Glory""). It's superb and just more pleasant on the page.
I should mention that somewhere in between these two is Namiki Blue. A great performer and a bit more lively than the Tsuyu-kusa in my opinion. "